Internal combustion engine-electric power unit



A. BRUNNER 2,178,355

INTERNAL COMBUSTION ENGINE-ELECTRIC POWER UNIT Oct. 31, 1939.

Filed Feb. 5, 1937 II "I 45 IN VENTOR AJUZF- Bid/V1767? nm inn WW M TC4,

' ATTORNEYS v UNITED STATES PATENT OFFICE INTERNAL COMBUSTIONENGINE-ELECTRIC POWER UNIT Adolf Erunner, Winterthur, Switzerland,assignor to Sulzer lFrres, ocit Anonyme, Winterthur, SwitzerlandApplication ll eloruarw 5, 1937, Serial No. 124,342 lln SwitzerlandFebruary 112, 1936 7 @llairns. (Cl. 299-40) This invention relates tointernal combustion to a rod l2 through which movement is impartedengine-electric power units and has for its object to a rack it forcontrolling the several fuel the provision of certain improvements inappumps M as hereinafter described. The lever paratus of this type. Theinvention relates parii is also connected through a link :5 to a leverticularly to apparatus for controlling the engine it having one endpivotally connected at ll to 55 speed, for maintaining the engine torqueconstant a lever hereinafter described, and the other end for a givenengine speed and for controlling the connected to a piston valve E8. Thevalve 58 conquantity of fuel supplied to the engine in actrois thesupply of pressure medium to a servocordance witl the engine speed. Itis an object motor cylinder 59 containing a piston 20 whose of thisinvention to provide means in combination rod is connected to a contactarm 2i of a rheoin with such apparatus for controlling the quantity stat22 whereby the excitation current for the of fuel injected into theengine which also conmain generator is regulated. The pressure metrolsthe timing of the commencement of the fuel dium for actuating the servopiston 29 is supplied injection. through an inlet conduit 23.

In accordance with the invention the comhi- The sleeve in of thegovernor 9 is opposed by 15 nation or arrangement of apparatus may besuch a spring 26 acted upon from above by a hollow that when thequantity of fuel injected during piston 25 movable within a cylinder 26.The inieach injection period is reduced, the commencetial tension of thespring 24 can be set as desired, ment of the injection period isretarded. It is a for example, by means of a hand wheel El havgg furtherobject of the invention to provide a corn ing a bevel wheel 28 whichdrives a bevel wheel bination or arrangement of apparatus whichonrotatable in a fixed bearing plate W and neiates in such way that whenthe quantity of ternally threaded to cooperate with a threaded fuelinjected during each injection period is reshaft 33. The shaft 3! actsat its lower end duced, the commencement of the said period is on thepiston and has at its upper end a part 5 advanced. 32 ofsquare-cross-section which cooperates with 25 These and other featuresof the invention will a corresponding guide at the upper end of the bebetter understood, if reference is made to the cylinder 26. The upperend of the rod 3% is conaccompanying drawing, taken in conjunctionnected, as shown at 33, to one end of a lever 3 with the followingdescription, in which: carried on a fixed pivot 35 and carrying at itsFigure 1 shows diagrammatically one arrangeother end the pivot ll. 39ment according to the invention; Instead of a single spring 24, thegovernor may Figure 2 is a vertical section on an enlarged be opposed byseveral springs which can be sucscale of one of the fuel pump cylindersincluded cessively rendered operative or inoperative as 11- in Figure 1;lustrated in the patent to O. Simmen No.

Figure 3 illustrates, on yet a larger scale, the 1,941,500. 35 relativepositions of the control edges on the Each of the fuel pumps is drivenby a cam 36 pump plunger andthe associated suction port; secured to theshaft l, as shown in Figure 2, the and cam 36 acting, during thedelivery stroke of the Figure 4 is a diagrammatic representation ofpump, on a roller 3'! carried at the lower end of a modifiedarrangement, also according to the a cylindrical guide member 38 so thatthe pump 49 invention. plunger 39 is moved upwards against the action Inthe arrangement of apparatus shown in Figof a spring 49. During thesuction stroke of the ure 1, the internal combustion engine I drives apump, the spring 40 moves the guide member 38 main current generator 2which supplies current and plunger 39 downwardly so as to draw fuel tothe traction motors 3 of a Diesel-electric vethrough a suction port 4|into the pump chamber, 5

hicle (not shown), the engine l driving also an this fuel beingdelivered to a corresponding enauxiliary current generator 4 whichsupplies the gine cylinder through a non-return valve 42 by excitationcurrent for the main generator 2. the next upward or delivery stroke ofthe The crankshaft 5 of the engine I drives, plunger 39.

through gear wheels 6, a shaft 1 which 1h turn e plunger 39 as twocontrol edges 43 and 44v transmits the drive through bevel wheels 8 to aso that when, during the delivery Stroke of the governor 9. The sleeveIn of the governor 9 is plunger 39, the'c edge 43 passes Over econnected to-a lever ll pivoted at a'nintermedisuction port 4|, deliveryof fuel past the nonate point to a fixed pivot and has secured theretoreturn valve 42 and injection into the correan arm H pivotally connectedat its lower end Spending engine cylinder commences. When, 55

towards the end of the delivery stroke, the control edge 44 passes overthe suction port 4|, fuel can flow through a groove 45 in the plunger 39from the pump chamber or cylinder 46 and back through the'suction port4|, the injection period being thus terminated.

The relative positions of the control edges 43, 44 and the suction port4| are indicated in Figure 3. When the rotational position of theplunger 39 is such that the port 4| lies on the line a1, the controledge 43 will close the suction port 4| late in the delivery stroke ofthe plunger and the control edge 44 will uncover the port 4| early inthe delivery stroke of the plunger. This position of the plunger 39enables the minimum fuel to be discharged; Points on the control edges43 and 44 are marked by a series of vertical lines 111, (la-a3, and (14.These points (Fig. 3) represent positions of the plunger 39 when theedges 43 and 44 intersect the opening 4|. In Fig. 2, the cam 36 is'marked with the characters a1, (12, I13 and (14, to indicate therelative positions of the cam corresponding to the positions of theedges 43 and 44 as indicated by the vertical lines a1, a2, a3 and cu inFig. 3. As shown in Fig. 3, the plunger 39 is set for maximum fueldelivery and as it is rotated so that the lines a2, a3 and (:4 aresuccessively coincident with the port 4| the quantity of fuel deliveredis successively increased. The difference between the distance I) asmeasured along one of the vertical lines from the control edge 43 to aline at right angle thereto which intersects the top of the port 4|, sayline a4, and the corresponding distance on the next line, for examplethe line as, represents the alteration in the timing of the commencementof injection by a rotation of the plunger 39. The distance 0 between thepoints of intersection of any one of the lines a1, 112, as or a4 and thebeing slotted at its lower end to cooperate with lugs 48 formed on thecooperating plunger 39. Thus, though each plunger can be rotated aboutits longitudinal axis by longitudinal movement of the rack l3, theplunger is free to reciprocate within'the member 41. When the rack ismoved so as to turn the pump plunger 39 in the direction of the arrow 49say from the position 11.1 to the position (12 the control edge 43 oneach plunger passes over and closes the suction port 4| earlier in thedelivery stroke and the control edge 44 uncovers the said suction portlater in the delivery stroke so that the effective distance 0, i. e.,the quantity of fuel injected, is increased. Conversely, when the rackis moved so as to turn the pump plungers in the direction opposite tothe arrow 49, say from the position corresponding to the line (14, tothat corresponding to the line as, the quantity of fuel injected intoeach engine cylinder will be reduced.

In Figure 1 the parts are shown in the position which they occupy whenequilibrium has been established between the load on the internalcombustion engine and the corresponding quantity of fuel injected for agiven engine speed as set by the hand wheel 21. If now the currentconditions of the main generator 2 are changed, for example, if thecurrent absorbed by the motors 3 changes so that the load is increased,the corresponding reduction in engine speed will cause the sleeve I!) toturn the lever II in the counterclockwise direction towards the positionX. The lever IE will thus be turned in the counter-clockwise directionabout the pivot I! so that the valve l8 will be raised and pressuremedium will be delivered from the conduit 23 into the cylinder l9 abovethe piston 20, pressure medium being discharged from beneath the piston29 through the lower end of the cylinder containing the valve Id. Thepiston 20 will thus move downwards so that the contact arm 2| is movedto increase the effective value of the resistance 22,

'in Figure 1. When the valve I8 is in the central position shown, thepiston 29 comes to rest in a new position so that the new setting of therheostat 22 is maintained. Since, therefore, the desired engine speed isrestored and the engine can now carry the load at the torque imposed, astate of equilibrium is again reached. If this is not the case, thevalve l8 will again automatically be adjusted and further adjustment ofthe rheostat 22 efiected until the valve I8 is restored to the positionshown.

When the load on the internal combustion engine I is reduced, the enginespeed rises and the valve 8 is moved downwardly so that the effectivevalue of the rheostat 22 is reduced and the excitation current of themain generator is increased. In the event of a rapid and considerableincrease or decrease in the load on the engine, the governor 9 may tendto hunt but the sleeve l0 will eventually reach the position ofequilibrium in accordance with the engine speed setting.

With a view to enabling different torque re quirements and fuel chargesto be set when the engine speed is to be changed, the effective lengthof the link system between the sleeve I0 and the valve I8 is adjusted bybodily altering the position of the pivot l'l, though this may, ifdesired, be effected by altering the effective length of the link l5.Thus, with a view to increasing the speed at which the engine is tooperate, the hand wheel 21 is turned so as to lower the rod 3|, towardsthe high speed setting indicated at m and thus increase the initialtension of the spring 24. The lever 34 thus will be turned in thecounter-clockwise direction about the pivot 35 so that the pivot I! willbe raised. In this way the valve I8 will be lowered so as to reduce theeifective value of the resistance 22 and increase the excitation current'of the main generator 2. Increase in the initial tension of the spring24 will result in temporary inward movement of the mass of the governor9 since the engine speed will not have changed. The resultingcounter-clockwise movement of the lever M will cause the rack 3 to bemoved to the right as shown in Figure 1, so as to increase the quantityof fuel injected into each internal combustion engine cylinder. At thesame time, the downward movement of the valve l8 due to raising of thepivot U will be, in part, counteracted by the resulting upward movementof the link l5 unless, at the same time, the current conditions in thearmature circuit of the main generator 2 are'changed so that suchconditions' already correspond to the new excitation :urrent requiredfor the higher engine speed. The alternation in the excitation currentof the pain generator 2 relieves the internal combustion engine i sothat its speed can increase to the new higher value which will then bemaintained substantially constant,

When the desired engine speed has been obtained, the valve l8 will havebeen restored to the normal or central position shown in Figure 1.Since, however, the pivot I1 is now in a new position, the position ofequilibrium of the governor sleeve ID will be altered in accordance withthe new speed. As a result, the position of equilibrium of the arm I Iwill be moved, towards the position 714, within its range of adjustment0, X, the adjustment of the arm Ii turning the plungers 39 of the fuelpumps in the direction of the arrow 49. In this way not only will thecommencement of fuel injection into each engine cylinder be advanced butthe termination of each injection period will be retarded, that is tosay the quantity of fuel injected during each injection period will beincreased, say, from the value c on the line 12 to the value c on theline as. Each injection period is thus increased and the quantity offuel injected is also increased;

Though in the construction described with reference to Figure 1 theratio of the quantityof fuel to be injected to the engine speed isgoverned by the position of the pivot H, i. e., the effective length ofthe link IS, in the modified arrangement shown in Figure 4 this ratio isadjusted, in accordance with a predetermined requirement. withalteration in the setting for the commencement of each fuel injection.To this end a cam track 50 is provided which can be moved along a fixedsupport or base 5| by means of a bell-crank lever 52 connected to therod 3i. A roller 53 at one end of the lever i6 is maintained in contactwith the cam track 50 by means of a spring 5 3.

If, for each engine speed which is to be set by the hand wheel 27, agiven engine torque is to be obtained, the end of each injection periodfor any given speed being determined by the control edge M, on the pumpplunger, the shape of the control edge 43 for determining thecommencement of each fuel injection and also the ratio of the torque tothe speed must be influenced in such a manner that for each engine speedset by the hand wheel 2'? the torque set shall correspond to the settingof the quantity of fuel injected by the pump. The cam track 50, which isadjusted by the hand wheel 27 in accordance with the engine speed setthereby, is advantageous in that the above rat o will be automaticallymaintained but can be readily altered.

The lever i6 is connected to a piston 55 which can reciprocate within aservocylinder 56, the su ply of pressure medium to which is controlledby l a piston valve 51 connected to the lever H. The piston 55 is alsoconnected through a rod 59 to the end 60 of the lever H, the rod 59being connected to one arm of a bell-crank lever 65, the other arm ofwhich is connected to the rod l2 i and rack l3; The pressure medium issupplied to the servomotor 56 through an inlet conduit 62.

The invention is advantageous in that since the torque is controlled inaccordance with the engine speed while the commencement-of fuelinjection and the quantity of fuel injected are simultaneouslycontrolled to suit the speed, an internal combustion engine-electricpower unit embodying the invention can be controlled in a manneranalogous to that available by regulation of com- 5 bustion engines inships, driving the propeller mechanically, the load of such enginesbeing dependent on the speed of the engine.

The timing of ignition in accordance with the engine speed is thusensured without the necessity for providing additional control means fortransmitting adjustments from the speed setting apparatus to the fuelpumps. This is particularly advantageous in vehicles where, owing tolimitation of space, the change-speed apparatus and the fuel pumps arearranged to opposite ends respectively of the internal combustionengine, since in view of the compact construction of internal combustionengines for driving vehicles, the number of rods or the like extendingalong the engine has necessarily to be limited for reasons ofaccessibility,

I claim:

1. Power apparatus which comprises in combination an internal combustionengine, fuel injectors for said engine, a main generator driven by theengine, governor means responsive to the engine speed for varying thecommencement of fuel injection during each stroke of the injectors andfor regulating the quantity of fuel injected into the engine during eachperiod of injection, and means connected to the governor means forvarying the load on said generator, whereby at each speed set for theengine the engine torque is maintained constant.

2. An internal combustion engine electric power unit which comprises incombination an internal combustion engine which is operable at variousspeeds, an electric generator driven by the engine, means for excitingthe generator, a fuel injection pump for the engine, governor meansresponsive to engine speed, said governor means controlling the meansfor exciting the generator, whereby for each speed set for the enginethe torque of the engine is automatically maintained constant inaccordance with the engine speed, means for varying the timing of fuelinjection in the engine, means for varying the quantity of fueldelivered by said injection pump and means operatively' coupling themeans for varying the quantity of fuel delivered by the pump and themeans for timing the fuel injection, said governor means controlling themeans for varying the quantity of fuel delivered by the pump.

3. An internal combustion engine electric power unit which comprises incombination an internal combustion engine, an electric generator drivenby the engine, means for the excitation of said generator, a fuelinjection pump for the engine, a governor responsive to the enginespeed, means for setting the governor at various engine speeds, meanscontrolled by the governor for varying the excitation means, said lastmentioned means being operatively connected to said setting means,whereby for each speed set for the engine the torque of the engine isautomatically maintained constant in accordance with the engine speed,means for varying the timing of fuel injection in the engine, and meansfor varying the quantity of fuel delivered by the injection pumpcontrolled by the governor and coupled to the means for varying thetiming of fuel injection.

4. Power apparatus which comprises in combination an internalcombustion. engine which is operable at various speeds, a fuel injectorfor the engine, a main electrical generator driven by the engine, anauxiliary current generator for supplying the excitation current for themain generator, governor means responsive to the engine speed forregulating the quantity of fuel injected into the engine and foradjusting the timing of commencement of injection of fuel during eachinjection stroke of the injector, and means operatively coupled to thegovernor means for varying the excitation current, whereby for eachspeed set for the engine the torque of the engine is automaticallymaintained constant in accordance with engine speed.

5. Power apparatus which comprises in combination an internal combustionengine which is operable at various speeds, a fuel injector for theengine the plungers of which are driven by the engine, a main electricgenerator driven by the engine, an auxiliary current generator for theexcitation of said main generator, a governor driven by the engine, saidplungers being adjusted by the governor and having control edges forregulating the quantity of the fuel injected and the timing ofcommencement of fuel injection by the injector, and means operativelyconnected with and responsive to the governor for varying saidexcitation, whereby for-each speed set for the engine the torque of theengine is automatically maintained constant in accordance with enginespeed.

6. A power unit in accordance with claim 2 in which the fuel injectorcomprises a cylinder, a plunger reciprocable in the cylinder, an inletport in said cylinder, means operatively associated with the plunger foradjusting the period during the plunger stroke when fuel is admittedthrough the inlet port, and means for by-passing fuel from the cylinder.

7. A power unit according to claim. 3 in which the fuel pump comprises acylinder, a plunger reciprocable and rotatable in the cylinder, and themeans for controlling the timing of commencement of fuel injectionduring each stroke of the pump is effected by rotation of the plunger.

ADOLF BRUNNER.

